Superoxide dismutase mimics for the treatment of ocular disorders and diseases

ABSTRACT

The use of SOD mimics particularly pentaazacycle Mn (II)  complex SOD mimics, for the treatment of AMD, DR, and retinal edema is disclosed.

The present application is a continuation of U.S. patent applicationSer. No. 10/498,721 filed Jun. 14, 2004 (now allowed), which is theNational Stage of International Application Serial No. PCT/US2002/039037filed Dec. 6, 2002, which claims benefit U.S. Provisional ApplicationSer. No. 60/340,389 filed Dec. 14, 2001.

The present invention relates to mimics of the enzyme superoxidedismutase for the treatment of the exudative and non-exudative forms ofage-related macular degeneration, diabetic retinopathy, and retinaledema.

BACKGROUND OF THE INVENTION

Age-related macular degeneration (AMD) is the most common cause ofvision impairment in the elderly population in western countries. Theexudative or “wet” form of AMD is characterized by excessiveneovascularization of the choroid, leading to retinal detachment andvision loss. The non-exudative or “dry” form is characterized by theaccumulation of cellular debris called drusen in Bruch's membrane belowthe retinal pigmented epithelium (RPE). Exudative AMD, which occurs in aminority of patients with AMD, but is the more aggressive form of thedisease, can be treated with limited success by laser photocoagulationtherapy or photodynamic therapy. The latter procedure involves dosing ofthe affected area with a compound which, when irradiated with theappropriate wavelength of light, generates a reactive intermediate thatdestroys surrounding blood vessels. Currently there is no acceptedtherapy for the treatment of non-exudative AMD.

The visual cycle begins in photoreceptor cells with the absorption of aphoton by an opsin-bound Schiff base of 11-cis retinal, which isomerizesto the corresponding all-trans retinal derivative. Release of theall-trans retinal from opsin is followed by condensation withphosphatidylethanolamine to form the new Schiff base NRPE (for N-RetinylPhosphatidyl Ethanolamine). The NRPE so formed is transported across thephotoreceptor cell outer membrane, where it is hydrolyzed to all-transretinal. Enzymatic reduction to all-trans retinol is followed bytransport into the RPE cell, where the compound is enzymaticallyisomerized to 11-cis retinol and oxidized to 11-cis retinal. Thiscompound is transported back to the photoreceptor cell, where it formsan opsin-bound Schiff base to complete the cycle.

Besides helping to complete the visual cycle by recycling retinal, animportant function of RPE cells is to support the continuous remodelingof retinal photoreceptors by phagocytosing their discarded outersegments and digesting them in RPE cell lysosomes. With age occurs theaccumulation of a non-digestible pigment called lipofuscin in thelysosomes (the appearance of drusen is thought to correspond tolipofuscin accumulation). Lipofuscin absorbs light in the blue part ofthe spectrum and fluoresces in the yellow part of the spectrum. Thisfluorescence transfers energy to nearby oxygen, which becomestransformed into reactive oxygen species (ROS), such as superoxide ion.These ROS oxidize lysosomal membrane phospholipids, destroying membraneintegrity. With membrane integrity breached the toxic contents of thelysosome leach into the cytosol, leading to RPE cell death. Withouttheir supporting RPE cells retinal photoreceptors cannot participate inthe visual transduction system, thus leading to blindness (for a review,see Winkler, et. al., Mol. Vision, Vol. 5:32, 1999, online journal;http://www.molvis.org/molvis/v5/p32; CA 132:235390).

Nakanishi and co-workers have elucidated the structure of and chemicallysynthesized the major fluorescent constituent of lipofuscin, called A2E(Nakanishi et. al., Proc. Natl. Acad. Sci. USA, Vol. 95:14609-14613,1998, and references therein). This compound is thought to resultbiosynthetically from isomerization of electrophilic NRPE to thenucleophilic enamine 1, followed by condensation with another moleculeof all-trans retinal to form azatriene 2, electrocyclic ring closure todihydropyridine 3, autoxidation to the N-(2-hydroxyethyl)pyridiniumspecies A2PE, and enzyamtic hydrolysis of the phosphate ester by theenzyme phospholipase D to afford A2E. The chemical structure of A2E-amolecule with two large hydrophobic “tails” and a charged polar“head”-suggests a detergent-like propensity to breach cell membranes.Along with its photooxidative capabilities, this may form an importantcomponent of the compound's toxic effects on RPE cells (for a review,see: Nakanishi et. al., Bioorganic and Medicinal Chemistry Letters, Vol.11:1533-1540, 2001).

The key role of defective transport of all-trans retinal out of thephotoreceptor cell in the AMD disease process has been highlighted bythe discovery that a genetic mutation that when homozygously presentleads to a rare rapid macular degeneration called Stargardt's Diseasemay be associated, when heterozygously expressed, with non-exudative AMD(Dean et. al., Science, Vol. 277:1805-1807, 1997). The gene is calledthe ABCR gene (for ATP Binding Cassette Transporter Retina), whoseprotein product (also called rim protein) utilizes the energy releasedupon ATP hydrolysis to transport molecules across cell membranes. It isthought that the transporter's substrate is the Schiff base NRPEmentioned above. Absent sufficient functional transporter protein, thesubstrate NRPE accumulates in the photoreceptor cell instead of beingshuttled out for reduction to retinol. Condensation with a molecule ofall trans-retinal liberated from opsin and further reaction as mentionedabove produces A2E. The A2E is ingested by RPE cells with the rest ofthe photoreceptor cell outer segment, where it accumulates in thelysosome. Supporting this hypothesis is the disclosure by Travis et. al.that A2E accumulation in RPE cells occurs much more rapidly in mice thatare homozygously mutant in the ABCR gene, as compared to normal controls(Travis et. al., Proc. Natl. Acad. Sci. USA, Vol. 97:7154-7159, 2000).

Several studies have concluded that exposure of lipofuscin to light andoxygen under conditions mimicking those present in the retina leads tocell membrane peroxidation and cell death. Wihlmark et. al. disclosedthat blue light irradiation of RPE cells with lipofuscin-loadedlysosomes increased cell membrane peroxidation and decreased cellviability, as compared to controls irradiated in the absence oflipofuscin (Wihlmark et. al., Free Radical Biol. Med. Vol. 22:1229-1234,1997). Boulton and Shamsi have disclosed that dosing of cultured RPEcells with lipofuscin and exposing them to light decreased cellviability by over 40% after 24 hours and decreased lysosomal enzymaticand antioxidant activity, including that of superoxide dismutase (SOD)(Boulton and Shamsi, Invest. Opthalmol. Vis. Sci., Vol. 42:3041-3046,2001).

From this and other evidence, it is clear that certain defects in thebody's natural defense mechanisms for dealing with toxic by-products ofoxidative metabolism may play an important role in the development ofAMD. One important component of this defense system is the SOD enzymefamily. These enzymes contain a low valent metal (either Mn^(II) or aCu^(I)/Zn^(I) binuclear linkage) which catalyze the disproportionationof the highly reactive superoxide radical anion to the less toxicentities O₂ and H₂O₂. If not quenched the superoxide anion can (via itsprotonated form) abstract hydrogens from the allylic sites of fattyacids, leading to membrane damage. Additionally superoxide anion canreact with NO to produce peroxynitrite, a potent oxidizing agent that isbelieved to be an important player in the untoward biological effects ofexcessive NO production.

The potential importance of SOD in enhancing RPE cell viability issuggested by the disclosure of Boulton et. al, who. have reported thatthe damaging effects caused by irradiation of lipid membranes, proteins,and enzymes in the presence of lipofuscin can be significantly reducedby the addition of SOD (Boulton et. al., J. Biol. Chem., Vol.274:23828-23832, 1999). Even with respect to exudative AMD, a recentstudy in Japanese subjects disclosed a significant correlation betweenthis form of the disease and a mutation in the SOD gene, correspondingto a valine/alanine substitution in the targeting sequence of the enzyme(Isashiki et. al., Am. J. Opthalmol., Vol. 130:769-773, 2000). Thus,enhancing SOD function may be a viable target for preventing thedevelopment of both the exudative and non-exudative forms of AMD.

Oxidative stress also contributes to diabetes induced vascular andneural dysfunction. All forms of diabetes result in the development ofdiabetes specific microvascular pathology of the retina, renalglomerulus and peripheral nerve (M. Brownlee, “Biochemistry andMolecular Cell Biology of Diabetic Complications”, Nature, Vol.414:813-820, 2001). A prime source of the oxidative insult associatedwith diabetes is elevated levels of superoxide. Release of superoxidewas detected in human blood vessels isolated from, patients withdiabetes (Guzik, et al., “Mechanisms of Increased Vascular SuperoxideProduction in Human Diabetes Mellitus” Circulation, Vol. 105:1656-62,2002). Sources of superoxide include the vascular tissues andpolymorphonuclear leukocytes (Shurtz-Swirski et al., “Involvement ofPeripheral Polymorphonuclear Leukocytes in Oxidative Stress andInflammation in Type 2 Diabetic Patients,” Diabetes Care, Vol.24:104-110, 2001). Superoxide Dismutase mimics have been shown to delaythe onset of diabetes (AEOL10113—Piganelli, et al., “AMetalloporphyrin-Based Superoxide Dismutase Mimic Inhibits AdoptiveTransfer of Autoimmune Diabetes by a Diabetogenic T-cell Clone,”Diabetes, Vol. 51:347-55, 2002.) in a cloned cell and prevented vascularand neural dysfunction in diabetic rats (M40403—Coppey, et al., “Effectof M40403 Treatment of Diabetic Rats on Endoneurial Blood Flow, MotorNerve Conduction Velocity and Vascular Function of Epineural Arteriolesof the Siatic Nerve,” British Journal of Pharmacology, Vol. 134:21-9,2001). In patients with diabetic retinopathy serum level of lipidperoxides are higher than in healthy normals or patients with diabetesthat do not have diabetic retinopathy. While levels of SOD remain thesame in diabetics and normals, levels of ascorbic acid, a keyanitoxidant, are lower in all diabetics (Gurler, et al., “The Role ofOxidative Stress in Diabetic Retinopathy” Eye, Vol. 14:73035, 2000) Theresults of these studies suggest that endogenous antioxidant mechanismsare overwhelmed in patients with diabetic retinopathy.

The use of intravenously dosed Mn SOD itself to treat or preventoxidative stress-related tissue injury in humans, such as tissue damagedue to cerebral or myocardial ischemia-reperfusion injury, has beenunsuccessful due to bioavailability and immunogenic issues. Theseproblems are thought to be due to the fact that Mn SOD is a highmolecular weight species. A low molecular weight compound that catalyzessuperoxide disproportionation with efficiency comparable to endogenousMn SOD would be a good candidate for minimizing the aforementioned sideeffects. Salvemini et. al. have disclosed a class of Mn(II)-pentaazamacrocycle complexes as low molecular weight SOD mimics. For example, ina rat model of intestinal ischemia-reperfusion, 90% of animals dosedwith 1 mg/kg of compound 4 survived after 4 h, compared to 0% survivalfor untreated animals [Salvemini, et. al., Science, Vol. 286:304, 1999;WO 98/58636; Salvemini, et al., Drugs Future, Vol. 25(10):1027, 2000],These compounds have also been disclosed for enhancing the stability ofimplanted biopolymeric prosthetic devices (including ocular implants;Ornberg et. al., WO 00/72893 A2) and for the treatment of pain(Salvemini et. al., U.S. Pat. Nos. 6,180,620 B1 and 6,214,817B1).

The use of certain Mn-salen complexes as SOD and catalase mimics withtherapeutic activity has also been disclosed. For example, compound 5has been shown to be neuroprotective in a rat stroke model (Baker et.al., J. Pharmacol. Exp. Ther., Vol. 284:215-221, 1998; Doctrow et. al.,J. Med. Chem., Vol. 45:4549-4558, 2002), while compound 6 was found toincrease the lifespan of mice that were deficient in endogenousexpression of the enzyme superoxide dismutase 2 (Melov et. al., J.Neurosci., Vol. 21:8348-8353, 2001).

Other investigators have reported the use of antioxidant compounds totreat ocular diseases. Crapo et. al., have disclosed the use ofporphyrin-containing SOD mimics for treating glaucoma and maculardegeneration (Crapo et. al., U.S. Pat. Nos. 5,994,339 and 6,127,356).Campbell et. al. have disclosed the use of certain bipyridyl Mn(II orIII)phenolate complexes for treating free-radical associated diseases(Campbell et. al., U.S. Pat. No. 6,177,419 B1). Levin has disclosed theuse of carvedilol and its derivatives and metabolites as scavengers ofROS to reduce retinal ganglion cell death (WO 00/07584 A2). Brownlee hasdisclosed the use of a manganese tetrakis(benzoic acid) porphyrin forreducing ROS accumulation under high glucose conditions for treatingdiabetic retinopathy (Brownlee, WO 00/19993 A2). The stable free radical4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, a metal-free SOD mimic,has been reported to inhibited light-induced retinal damage in albinorats (Wang et. al., Res. Commun. Mol. Pathol. Pharmacol., Vol.89:291-305, 1995). However, in none of these reports were the compoundsof the present invention disclosed or suggested for the treatment ofAMD.

SUMMARY OF THE INVENTION

This application is directed to the use of mimics of the enzyme,superoxide dismutase to treat persons suffering from the exudative andnon-exudative forms of AMD, diabetic retinopathy, which includespreproliferative diabetic retinopathy (collectively DR) and retinaledema.

DETAILED DESCRIPTION OF THE INVENTION

Posterior segment neovascularization is the vision-threatening pathologyresponsible for the two most common causes of acquired blindness indeveloped countries: exudative age-related macular degeneration (AMD)and proliferative diabetic retinopathy (PDR). Currently the onlyapproved treatments for the posterior segment NV that occurs duringexudative AMD are laser photocoagulation or photodynamic therapy withVisudyne®; both therapies involve occlusion of affected vasculaturewhich results in localized laser-induced damage to the retina. Surgicalinterventions with vitrectomy and membrane removal are the only optionscurrently available for patients with proliferative diabeticretinopathy. No strictly pharmacologic treatment has been approved foruse against posterior segment NV, although several different compoundsare being evaluated clinically, including, for example, anecortaveacetate (Alcon, Inc.), EYE 001 (Eyetech), and rhuFabV2 (Genentech) forAMD and LY333531 (Lilly) and Fluocinolone (Bausch & Lomb) for diabeticmacular edema.

In addition to changes in the retinal microvasculature induced byhyperglycemia in diabetic patients leading to macular edema,proliferation of neovascular membranes is also associated with vascularleakage and edema of the retina. Where edema involves the macula, visualacuity worsens. In diabetic retinopathy, macular edema is the majorcause of vision loss. Like angiogenic disorders, laser photocoagulationis used to stabilize or resolve the edematous condition. While reducingfurther development of edema, laser photocoagulation is acytodestructive procedure, that, unfortunately will alter the visualfield of the affected eye.

An effective pharmacologic therapy for ocular NV and edema would likelyprovide substantial efficacy to the patient, in many diseases therebyavoiding invasive surgical or damaging laser procedures. Effectivetreatment of the NV and edema would improve the patient's quality oflife and productivity within society. Also, societal costs associatedwith providing assistance and health care to the blind could bedramatically reduced.

It has now been discovered that certain SOD mimics are useful for thetreatment of AMD, DR, and retinal edema. These compounds are of formulaI:

wherein:R¹⁻²⁰ are independently H, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, aryl, heteroaryl, heterocycloalkyl, or heterocycloalkenyl,each of which is optionally substituted with an alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycloalkyl,heterocycloalkenyl, halo, trihalomethyl, acyl, alkoxycarbonyl,alkylsulfonyl, or arylsulfonyl group, or a free or functionally modifiedhydroxyl, amino, or thiol group;or two of the R groups on the same (e.g., R¹ and R², or R³ and R⁴, or R⁵and R⁶, etc.) or adjacent (e.g., R¹ and R³, or R³ and R⁵, or R⁶ and R⁷,etc.) sites, together with the carbon atoms to which they are attached,form an optionally unsaturated or aromatic C₃₋₂₀ carbocycle, thecarbocycle being optionally substituted with alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycloalkyl,heterocycloalkenyl, halo, trihalomethyl, acyl, alkoxycarbonyl,alkylsulfonyl, or arylsulfonyl group, or a free or functionally modifiedhydroxyl, amino, or thiol group;or two of the R groups on the same (e.g., R¹ and R², or R³ and R⁴, or R⁵and R⁶, etc.) or adjacent (e.g., R¹ and R³, or R³ and R⁵, or R⁶ and R⁷,etc.) sites, together with the carbon atoms to which they are attached,form an optionally unsaturated or aromatic C₂₋₂₀ nitrogen-containingheterocycle, the heterocycle being optionally substituted optionallysubstituted with alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,aryl, heteroaryl, heterocycloalkyl, heterocycloalkenyl, halo,trihalomethyl, acyl, alkoxycarbonyl, alkylsulfonyl, or arylsulfonylgroup, or a free or functionally modified hydroxyl, amino, or thiolgroup;it being understood that in all cases the nitrogens binding the Mncenter in the drawing for I will lack hydrogens when the nitrogen isalready trisubstituted (e.g., when the relevant nitrogen is part of apyridine ring);X, Y, and Z are pharmaceutically acceptable anions; andn is 0-3.

Compounds I of the present invention are known, and their syntheses aredisclosed in U.S. Pat. No. 6,214,817 B1, which is herein incorporated byreference.

As used herein, the terms “pharmaceutically acceptable anion” means anyanion that would be suitable for therapeutic administration to a patientby any conventional means without significant deleterious healthconsequences. Examples of preferred pharmaceutically acceptable anionsinclude chloride, bromide, acetate, benzoate, maleate, fumarate, andsuccinate.

The term “free hydroxy group” means an OH. The term “functionallymodified hydroxy group” means an OH which has been functionalized toform: an ether, in which an alkyl group is substituted for the hydrogen;an ester, in which an acyl group is substituted for the hydrogen; acarbamate, in which an aminocarbonyl group is substituted for thehydrogen; or a carbonate, in which an alkoxycarbonyl group issubstituted for the hydrogen. Examples of preferred groups includeOH,OC(O)CH₃, OCH₃, OPh, OCH₂Ph, and OC(O)Ph.

The term “free amino group” means an N₂. The term “functionally modifiedamino group” means an NH₂ which has been functionalized to form: analkoxyamino or hydroxyamino group, in which an alkoxy or hydroxy groupis substituted for one of the hydrogens; an alkylamino group, in whichan alkyl group is substituted for one or both of the hydrogens; anamide, in which an acyl group is substituted for one of the hydrogens; acarbamate, in which an alkoxycarbonyl group is substituted for one ofthe hydrogens; or a urea, in which an aminocarbonyl group is substitutedfor one of the hydrogens. Combinations of these substitution patterns,for example an NH₂ in which one of the hydrogens is replaced by an alkylgroup and the other hydrogen is replaced by an alkoxycarbonyl group,also fall under the definition of a functionally modified amino groupand are included within the scope of the present invention. Examples ofpreferred groups include NH₂, NHCH₃, N(CH₃)₂, NHPh, NHC(O)Ph, NHC(O)CH₃,NHC(O)OCH₃, and NHC(O)OPh.

The term “free thiol group” means an SH. The term “functionally modifiedthiol group” means an SH which has been functionalized to form: athioether, where an alkyl, aryl, cycloalkyl, heterocycloalkyl, alkenyl,cycloalkenyl, heterocycloalkenyl, alkynyl, or heteroaryl group issubstituted for the hydrogen; or a thioester, in which an acyl group issubstituted for the hydrogen. Examples of preferred moieties include SH,SPh, SC(O)CH₃, SCH₃, SC₂H₅, SC(CH₃)₃, S-cyclohexyl, SCH₂CO₂CH₃,SCH₂CO₂C₂H₅, SCH₂C(O)C₂H₅, and SCH₂C(O)CH₃.

The term “acyl” represents a group that is linked by a carbon atom thathas a double bond to an oxygen atom and a single bond to another carbonatom.

The term “alkyl” includes straight or branched chain aliphatichydrocarbon groups that are saturated and have 1 to 15 carbon atoms. Thealkyl groups may be substituted with other groups, such as halogen,hydroxyl or alkoxy. Preferred straight or branched alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl and t-butyl.

The term “cycloalkyl” includes straight or branched chain, saturated orunsaturated aliphatic hydrocarbon groups which connect to form one ormore rings, which can be fused or isolated. The rings may be substitutedwith other groups, such as halogen, hydroxyl, alkoxy, or lower alkyl.Preferred cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyland cyclohexyl.

The term “alkenyl” includes straight or branched chain hydrocarbongroups having 1 to 15 carbon atoms with at least one carbon-carbondouble bond. The chain hydrogens may be substituted with other groups,such as halogen. Preferred straight or branched alkeny groups include,allyl, 1-butenyl, 1-methyl-2-propenyl and 4-pentenyl.

The term “cycloalkenyl” includes straight or branched chain, saturatedor unsaturated aliphatic hydrocarbon groups which connect to form one ormore non-aromatic rings containing a carbon-carbon double bond, whichcan be fused or isolated. The rings may be substituted with othergroups, such as halogen, hydroxyl, alkoxy, or lower alkyl. Preferredcycloalkenyl groups include cyclopentenyl and cyclohexenyl.

The term “alkoxy” represents an alkyl group attached through an oxygenlinkage.

The term “carbonyl group” represents a carbon atom double bonded to anoxygen atom, wherein the carbon atom has two free valencies.

The term “alkoxycarbonyl” represents an alkoxy group bonded from itsoxygen atom to the carbon of a carbonyl group, the carbonyl group itselfbeing bonded to another atom through its carbon atom.

The term “aminocarbonyl” represents an amino group bonded from itsnitrogen atom to the carbon atom of a carbonyl group, the carbonyl groupitself being bonded to another atom through its carbon atom.

The term “lower alkyl” represents alkyl groups containing one to sixcarbons (C₁-C₆).

The term “halogen” represents fluoro, chloro, bromo, or iodo.

The term “aryl” refers to carbon-based rings which are aromatic. Therings may be isolated, such as phenyl, or fused, such as naphthyl. Thering hydrogens may be substituted with other groups, such as loweralkyl, or halogen.

The term “heteroaryl” refers to aromatic hydrocarbon rings which containat least one heteroatom such as O, S, or N in the ring. Heteroaryl ringsmay be isolated, with 5 to 6 ring atoms, or fused, with 8 to 10 atoms.The heteroaryl ring(s) hydrogens or heteroatoms with open valency may besubstituted with other groups, such as lower alkyl or halogen. Examplesof heteroaryl groups include imidazole, pyridine, indole, quinoline,furan, thiophene, pyrrole, tetrahydroquinoline, dihydrobenzofuran, anddihydrobenzindole.

Preferred compounds of the present invention include those of formula I,wherein:

R⁷R⁸C—N—CR⁹R¹⁰ forms a 5-8 membered saturated or unsaturated (includingaromatic) ring, the ring being optionally substituted with alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl,heterocycloalkyl, heterocycloalkenyl, halo, trihalomethyl, acyl,alkoxycarbonyl, alkylsulfonyl, or arylsulfonyl group, or a free orfunctionally modified hydroxyl, amino, or thiol group;R⁵, R⁶, R¹¹, R¹², R¹⁷, R¹⁸, R¹⁹, and R²⁰ are the same or different andare H or alkyl;R¹R²C—CR³R⁴ and R¹³R¹⁴C—CR¹⁵R¹⁶ are the same or different and form a 5-8membered saturated or unsaturated (including aromatic) ring, the ringbeing optionally substituted with alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, aryl, heteroaryl, heterocycloalkyl, heterocycloalkenyl,halo, trihalomethyl, acyl, alkoxycarbonyl, alkylsulfonyl, orarylsulfonyl group, or a free or functionally modified hydroxyl, amino,or thiol group;X and Y are chloride; andn is 0.

The most preferred compounds of the present invention include thefollowing:

The syntheses of these compounds is disclosed in U.S. Pat. No. 6,214,817B1.

The SOD mimics may be contained in various types of pharmaceuticalcompositions, in accordance with formulation techniques known to thoseskilled in the art. For example, the compounds may be included intablets, capsules, solutions, suspensions, and other dosage formsadapted for oral administration; solutions and suspensions adapted forparenteral use; and solutions and suspensions adapted for topicalophthalmic, depot, or intra-ocular injection. Solutions, suspensions,and other dosage forms adapted for depot, oral, intra-ocular injection,and topical ophthalmic administration, such as eye drops or tissueirrigating solutions, are particularly preferred for the prevention ortreatment of acute or chronic retinal or optic nerve head damage.Compositions can also be delivered topically to the eye according to theteachings in WO 96/05840, which is herein incorporated by reference.

The present invention is also directed to the provision of compositionsadapted for treatment of retinal and optic nerve head tissues. Theophthalmic compositions of the present invention will include one ormore SOD mimics and a pharmaceutically acceptable vehicle. Various typesof vehicles may be used. The vehicles will generally be aqueous innature. Aqueous solutions are generally preferred, based on ease offormulation, as well as a patient's ability to easily administer suchcompositions by means of instilling one to two drops of the solutions inthe affected eyes. However, the SOD mimics of the present invention mayalso be readily incorporated into other types of compositions, such assuspensions, viscous or semi-viscous gels, or other types of solid orsemi-solid compositions. Suspensions may be preferred for SOD mimicsthat are relatively insoluble in water. The ophthalmic compositions ofthe present invention may also include various other ingredients, suchas buffers, preservatives, co-solvents, and viscosity building agents.

An appropriate buffer system (e.g., sodium phosphate, sodium acetate orsodium borate) may be added to prevent pH drift under storageconditions.

Ophthalmic products are typically packaged in multidose form.Preservatives are thus required to prevent microbial contaminationduring use. Suitable preservatives include: benzalkonium chloride,thimerosal, chlorobutanol, methyl paraben, propyl paraben, phenylethylalcohol, edetate disodium, sorbic acid, polyquaternium-1, or otheragents known to those skilled in the art. Such preservatives aretypically employed at a level of from 0.001 to 1.0% weight/volume (“%w/v”).

The route of administration (e.g., topical, ocular injection,parenteral, or oral) and the dosage regimen will be determined byskilled clinicians, based on factors such as the exact nature of thecondition being treated, the severity of the condition, and the age andgeneral physical condition of the patient.

In general, the doses used for the above described purposes will vary,but will be in an effective amount to prevent or treat AMD, DR, andretinal edema. As used herein, the term “pharmaceutically effectiveamount” refers to an amount of one or more SOD mimics which willeffectively treat AMD, DR, and/or retinal edema in a human patient. Thedoses used for any of the above-described purposes will generally befrom about 0.01 to about 100 milligrams per kilogram of body weight(mg/kg), administered one to four times per day. When the compositionsare dosed topically, they will generally be in a concentration range offrom 0.001 to about 5% w/v, with 1-2 drops administered 1-4 times perday.

As used herein, the term “pharmaceutically acceptable carrier” refers toany formulation that is safe, and provides the appropriate delivery forthe desired route of administration of an effective amount of at leastone compound of the present invention.

The following Examples 1 and 2 are formulations useful for intraocular,periocular, or retrobulbar injection or perfusion.

Example 1

Component % w/v Compound of formula I 0.1 Dibasic sodium phosphate 0.2HPMC 0.5 Polysorbate 80 0.05 Benzalkonium chloride 0.01 Sodium chloride0.75 Edetate disodium 0.01 NaOH/HCl q.s. to pH 7.4 Purified water q.s.to 100%

Example 2

Component % w/v Compound of formula I 0.1 Cremophor EL 10 Tromethamine0.12 Boric acid 0.3 Mannitol 4.6 Edetate disodium 0.1 Benzalkoniumchloride 0.1 NaOH/HCl q.s. to pH 7.4 Purified water q.s. to 100%

Example 3

The following tablet formulation can be made pursuant to U.S. Pat. No.5,049,586, incorporated herein by reference.

Component % w/v Compound of formula I 60 Magnesium oxide 20 Corn starch15 Polyvinylpyrrolidone 3 Sodium 1 carboxymethylcellulose Magnesiumstearate 0.8

The invention has been described by reference to certain preferredembodiments; however, it should be understood that it may be embodied inother specific forms or variations thereof without departing from itsspirit or essential characteristics. The embodiments described above aretherefore considered to be illustrative in all respects and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing description.

1. A method for treating AMD, DR, and/or retinal edema in a patientwhich comprises administering to the patient in need of such treatment apharmaceutical composition formulated for intraocular, periocular, orretrobulbar injection or perfusion, wherein the composition comprises apharmaceutically effective amount of a compound of formula I:

wherein: R¹⁻²⁰ are independently H, alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, aryl, heteroaryl, heterocycloalkyl, or heterocycloalkenyl,each of which is optionally substituted with an alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycloalkyl,heterocycloalkenyl, halo, trihalomethyl, acyl, alkoxycarbonyl,alkylsulfonyl, or arylsulfonyl group, or a free or functionally modifiedhydroxyl, amino, or thiol group; or two of the R groups on the same(e.g., R¹ and R², or R³ and R⁴, or R⁵ and R⁶, etc.) or adjacent (e.g.,R¹ and R³, or R³ and R⁵, or R⁶ and R⁷, etc.) sites, together with thecarbon atoms to which they are attached, form an optionally unsaturatedor aromatic C₃₋₂₀ carbocycle, the carbocycle being optionallysubstituted with alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,aryl, heteroaryl, heterocycloalkyl, heterocycloalkenyl, halo,trihalomethyl, acyl, alkoxycarbonyl, alkylsulfonyl, or arylsulfonylgroup, or a free or functionally modified hydroxyl, amino, or thiolgroup; or two of the R groups on the same (e.g., R¹ and R², or R³ andR⁴, or R⁵ and R⁶, etc.) or adjacent (e.g., R¹ and R³, or R³ and R⁵, orR⁶ and R⁷, etc.) sites, together with the carbon atoms to which they areattached, form an optionally unsaturated or aromatic C₂₋₂₀nitrogen-containing heterocycle, the heterocycle being optionallysubstituted optionally substituted with alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycloalkyl,heterocycloalkenyl, halo, trihalomethyl, acyl, alkoxycarbonyl,alkylsulfonyl, or arylsulfonyl group, or a free or functionally modifiedhydroxyl, amino, or thiol group; it being understood that in all casesthe nitrogens binding the Mn center in the drawing for I will lackhydrogens when the nitrogen is already trisubstituted (e.g., when therelevant nitrogen is part of a pyridine ring); X, Y, and Z arepharmaceutically acceptable anions; and n is 0-3.
 2. The method of claim1, wherein for the compound of formula I: R⁷R⁸C—N—CR⁹R¹⁰ forms a 5-8membered saturated or unsaturated (including aromatic) ring, the ringbeing optionally substituted with alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, aryl, heteroaryl, heterocycloalkyl, heterocycloalkenyl,halo, trihalomethyl, acyl, alkoxycarbonyl, alkylsulfonyl, orarylsulfonyl group, or a free or functionally modified hydroxyl, amino,or thiol group; R⁵, R⁶, R¹¹, R¹², R¹⁷, R¹⁸, R¹⁹, and R²⁰ are the same ordifferent and are H or alkyl; R¹R²C—CR³R⁴ and R¹³R¹⁴C—CR¹⁵R⁶ are thesame or different and form a 5-8 membered saturated or unsaturated(including aromatic) ring, the ring being optionally substituted withalkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl,heterocycloalkyl, heterocycloalkenyl, halo, trihalomethyl, acyl,alkoxycarbonyl, alkylsulfonyl, or arylsulfonyl group, or a free orfunctionally modified hydroxyl, amino, or thiol group; X and Y arechloride; and n is O.
 3. The method of claim 3, wherein the compound isselected from the group consisting of:


4. The method of claim 1, wherein the pharmaceutical composition furthercomprises diabasic sodium phosphate, hydroxypropyl methylcellulose(HPMC), polysorbate 80, and benzalkonium chloride.
 5. The method ofclaim 4, wherein the pharmaceutical composition further comprises sodiumchloride, edentate disodium, and has a pH of 7.4.